1. Field of the Invention
The present invention relates to filter bags, and more particularly to a seamless filter bag with an integral sealing means.
2. Discussion of the Relevant Art
When providing filter units for industrial operations, such as chemical or paint spraying systems, it is a common practice to provide a filter with an inlet for the unfiltered liquid and an outlet for the filtered liquid with some type of filter medium disposed between the inlet and outlet to remove the contaminant in the liquid. Generally these systems are under relatively high pressure and there have been numerous attempts to maintain the integrity of the filtering system. Generally with a filter of this type, a seal or multiple seals are required to retain the fluid in the filter housing. In addition to a seal, which is provided to prevent mixing of the unfiltered liquid with the filtrate, the filter apparatus includes a rigid housing into which is placed a filter basket. The filter bag is centrally disposed within the filter basket with the filter material comprising fabric, which must be supported by the aforementioned basket. The mesh of the filter bag determines the degree of filtering to be afforded to the liquid passing therethrough. The cover of the housing when closed over the filter bag and filter basket insures that the system will not leak or overflow when the liquid is poured therein. The covers known in the prior art will generally crush an O-ring or other type of gasket when placed in its closed position and locked. Generally, one or more of these gaskets or O-rings are deformed by the cover when it is locked in an attempt to stop the filtered material from being contaminated with the filtrate that have been removed by the filter.
Over the years many different methods utilizing several different crushing techniques have been utilized, but the problem of containing the integrity of the filtered material still exists.
A typical crushing of an elastomeric provided on the filter bag is crushed between the filter tank and its cover and it acts to both hold the liner in position in use, as well as, providing a seal between the filter housing and the cover. However, this type of construction has not been completely successful.
U.S. Pat. No. 4,948,504 to Kierdorf, et al., issued Aug. 14, 1990, again utilizes a filter sealing element disposed about an annular filter bag includes an open groove adapted to receive an O-ring member which hereagain gets crushed by the cover of the filter housing assembly and, although successful to some extent, still is not as effective as generally required.
U.S. Pat. No. 3,774,769 to Smith, issued on Nov. 27, 1973, includes a system of grooves provided in a flange member in order to accept sealing O-ring members, which were crushed by the cover in an attempt to provide a seal between the filtered and unfiltered liquid medium.
All of these attempts to solve the general problem of maintaining the isolation between the filtered and unfiltered material as well as preventing leakage to the outside environment are not completely successful, since continuous attempts have been made with other means to attempt to provide the necessary seal required.
The present invention overcomes the shortcomings known in the prior art by providing a seamless filter bag with an integral sealing means that is used in a filter housing with a removable filter basket. A handle is provided for ease in removing the filter bag when it becomes full so that it may readily be replaced. The handle also includes indicia thereon, which indicates the manufacturer of the filter bag and may include the rating of the filter (size of the particles to be removed), which normally appears on the bag itself.